The present invention relates to apparatus and methods for cleaning annular filters and, more particularly, to an apparatus and method for cleaning accumulated fibrous material from a cylindrical textile filter of the type utilized in textile processing systems.
The textile dyeing and like wet processing machinery, it is common for the mechanical and fluid forces exerted on the fabric material being processed to cause a small proportion of the fibers in the material to be released from the body of the material. Such fibers typically tend to become entrained in the treating fluid as it flows through the machine's fluid circulation system and to gradually accumulate at susceptible locations within the circulation system. Over time, fibrous accumulations of this sort restrict the normal flow of treating fluid and, in extreme cases, may require stoppage of the machine for cleaning.
To prevent fluid flow restriction and to minimize machine stoppages, it has become common practice to utilize a filtration arrangement in the fluid circulating system of such textile wet processing machinery. Commonly, a cylindrical filter having an annular filtering media of perforated stainless steel is utilized as a filter, with the direction of fluid flow through the filter typically being radially outwardly from the interior of the filter. Over the cource of normal operation, fibrous material released from fabrics under treatment is deposited about the interior surface of the annular filter media, requiring the filter to be periodically removed from the et processing machine for cleaning of the filtered accumulation.
While such filtering systems advantageously serve their intended purpose of separating fibrous material from the circulated treating fluid, the periodic cleaning of the filters is obtain a difficult task in that the necessarily small perforations of the filter media and the relatively high fluid flow rates with attendant fluid turbulence produced by conventional wet processing machines combine to cause the filtered fibrous material to be projected through the filter media perforations and to become entangled with one another both at the interior and exterior surfaces of the filter media. As a result, the accumulation of filtered fibrous material becomes firmly lodged and entangled in the filter media and cannot be simply lifted or washed from the interior surface of the filter media.
Conventionally, such filters are manually cleaned by an operator utilizing a pressurized water hose which, while generally effective, has several disadvantages. While the use of a pressurized stream of water is normally effective in disentangling accumulated fibrous material from the filter media in a localized area at which the water stream is directly applied, there is a tendency of the water stream, particularly at higher pressures, to carry the dislodged material across the interior of the filter and redeposit the material at the opposite interior side of the filter media. Overall, this manual filter cleaning process is time-consuming and annoying to complete. In fact, it is not uncommon for filter cleaning by this technique to require twenty minutes or more of operator time.